Zika virus

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Zika virus is a mosquito-borne flavivirus that can cause serious birth defects and other health problems. It is primarily transmitted through the bite of an infected Aedes species mosquito, such as A. aegypti or A. albopictus. Zika infection during pregnancy can lead to congenital Zika syndrome, a pattern of birth defects that includes microcephaly, where the baby's head is smaller than expected due to abnormal brain development. Most people infected with Zika have mild or no symptoms, but the virus can also be passed from mother to fetus, through sexual contact, or blood transfusion. There is no specific treatment or vaccine for Zika - the best prevention is avoiding mosquito bites.

For example, during the 2015-2016 Zika outbreak, Brazil saw a significant increase in babies born with microcephaly and other congenital abnormalities linked to the virus. This led to a global public health emergency.

Terms

• Aedes mosquitoes: The type of mosquitoes, especially A. aegypti and A. albopictus, that are the primary vectors for transmitting Zika virus to humans. These mosquitoes are active during the day and typically breed near standing water.
  Example: Aedes aegypti mosquitoes are well-adapted to urban environments and often lay eggs in man-made containers.

• Congenital Zika syndrome: A distinct pattern of birth defects and disabilities found among fetuses and babies infected with Zika virus during pregnancy. It features severe microcephaly, decreased brain tissue, damage to the back of the eye, limited range of joint motion, and too much muscle tone restricting movement.
  Example: Around 5-15% of infants born to women infected with Zika during pregnancy develop some degree of congenital Zika syndrome.

• Flavivirus: A genus of viruses in the family Flaviviridae, which includes Zika virus, dengue virus, yellow fever virus, and West Nile virus. Many flaviviruses are transmitted by mosquitoes or ticks and can cause serious human diseases.
  Example: Zika virus is closely related to dengue virus, another flavivirus spread by Aedes mosquitoes.

• Microcephaly: A birth defect where a baby's head is smaller than expected compared to babies of the same sex and age. It is often due to abnormal brain development and is a key feature of congenital Zika syndrome.
  Example: Babies with microcephaly often have significant intellectual disability and developmental delays.

Analogy

Imagine Zika as an uninvited guest who slips into a party - in this case, the human body - by hitching a ride with a mosquito. Once inside, Zika starts causing trouble, especially if it crashes a baby shower happening in the womb. It disrupts the baby's development, like an unruly guest knocking over the carefully arranged decorations. The result is a baby born with congenital Zika syndrome, much like a party venue left in shambles by the unwelcome visitor.

For instance, a pregnant woman bitten by a Zika-carrying mosquito may unknowingly pass the virus to her unborn child, leading to microcephaly and other birth defects that affect the baby's brain, eyes, and limbs.

Misconception

Many people incorrectly believe that Zika virus only affects pregnant women and their babies. While it's true that Zika can cause devastating birth defects when contracted during pregnancy, the virus can infect anyone. Most people don't develop serious symptoms, which leads to the misconception that Zika is harmless to the general population.

In reality, Zika has been linked to Guillain-Barré syndrome, a rare disorder where the body's immune system attacks the nerves, leading to muscle weakness and sometimes paralysis. During the 2015-2016 outbreak, several countries affected by Zika reported increases in Guillain-Barré cases.

History

1. 1947: Zika virus is first discovered in a rhesus monkey in Uganda's Zika Forest, hence its name.

2. 1952: The first human cases of Zika are detected in Uganda and Tanzania.

3. 1960s-1980s: Zika spreads to equatorial Asia, with human infections reported in several countries.

4. 2007: A major Zika outbreak occurs on Yap Island, Micronesia, the first time the virus is detected outside of Africa and Asia.

5. 2013-2014: Zika outbreaks are reported in French Polynesia, Easter Island, the Cook Islands, and New Caledonia.

6. 2015-2016: Zika spreads to the Americas, with Brazil at the epicenter. The outbreak reveals that Zika can cause congenital abnormalities and Guillain-Barré syndrome, prompting the WHO to declare a Public Health Emergency of International Concern.

7. 2016-present: Zika continues to circulate at low levels in many countries. Research into vaccines and treatments is ongoing, and the long-term impacts of congenital Zika syndrome become clearer as affected children grow and develop.

How to use it

1. When planning travel, check if your destination has a risk of Zika. If so, take steps to prevent mosquito bites, such as using repellent, wearing long sleeves and pants, and staying in places with window screens or air conditioning. Pregnant women should avoid travel to Zika-affected areas.

2. If you or your partner live in or travel to an area with Zika, use condoms or abstain from sex during pregnancy to avoid sexual transmission of the virus. Wait at least 3 months before trying to conceive if the male partner may have been exposed to Zika.

3. At home and in your community, help control mosquitoes by eliminating standing water where they lay eggs. Empty and scrub items like tires, buckets, planters, toys, or trash containers weekly. Tightly cover water storage containers so mosquitoes can't get inside to lay eggs.

Facts

• Zika is named after Uganda's Zika Forest, where the virus was first discovered in a rhesus monkey in 1947.

• Around 80% of people infected with Zika have no symptoms, making it difficult to track the virus's spread.

• Zika can be sexually transmitted by both men and women, even if they don't have symptoms.

• During the 2015-2016 outbreak, over 30 countries reported cases of congenital Zika syndrome, with Brazil confirming more than 2,600 cases.

• In addition to microcephaly, congenital Zika syndrome can cause seizures, hearing and vision problems, and developmental delays in affected infants.